1. The Field of the Invention
The invention relates to selectively replaying voice data during a communication session. In particular, embodiments of the invention are directed to selectively replaying voice data during network-based instant connect communication (also known as Push to Talk®) and during conventional telephone communication.
2. The Relevant Technology
Mobile telephones are some of the most common communication devices in use today. As the popularity of mobile telephones and other telephony-enabled wireless devices such as personal digital assistants increases, the ways in which these devices are used also grows. One application of mobile telephone technology is to use mobile telephones as if they were two-way radio devices or “walkie-talkies.” The ability to use mobile telephones as walkie-talkies is often referred to as “push-to-talk”. Communication in a push-to-talk system can be one-to-one or one-to-many. One example of a push-to-talk system is Nextel's iDEN-based Push to Talk® (also known as Direct Connect™) service.
Push-to-talk systems may be implemented using standard Voice Over Internet Protocol (VoIP) technologies or other technologies, where voice data is sent in digital form over data networks. Such push-to-talk systems are hereinafter referred to as “network-based instant connect systems”, and they can be deployed in various networks, including circuit-switched networks and packet data networks, and may use any combination of wireless and wireline devices.
Network-based instant connect communication allows a sender to speak to a recipient without the customary procedure of dialing a telephone number and waiting for the recipient to answer. Network-based instant connect communication services combine the convenience of near-instantaneous connection between users with the range and security afforded by a network. Once an instant connect session is established over the network, the voice data transmitted from a sender is played on the recipient's device without any action on the part of the recipient. This is in contrast to a regular telephone call where the recipient is required to manually respond to a ringing telephone.
Because network-based instant connect calls are designed to mimic walkie-talkie communication, the communication channel is used in a half-duplex manner, meaning that voice data can only flow in one direction at a time. The ability to transmit voice data is often referred to as “having the floor”. In a network-based instant connect communication, the sender typically sends a floor request signal to a server in the network by pressing the talk button on a suitably enabled wireless device. Once the floor is granted, the sender may speak to the recipient until the talk button is released. The recipient of the voice data who does not have the floor can merely receive the voice data and cannot take the floor until the sender relinquishes the floor.
As noted above, one general feature of network-based instant connect communications is that, if the recipient's device is powered on and is in a mode to accept incoming calls, any incoming network-based instant connect calls result in the recipient's device automatically outputting voice data. The recipient of an instant connect call does not typically control when the instant connect call is received and there may be situations when the recipient does not understand or cannot clearly hear what the sender said.
The inability to understand a sender in an instant connect call can occur, for example, when the recipient is in a noisy environment. Construction sites, restaurants, and traffic are examples of environments where a recipient of an instant connect call may be unable to understand the sender. The inability to understand a sender can also occur when the voice data is incomplete. During instant connect communication, voice data is often sent over an IP network using a connectionless protocol that does not guarantee delivery of the packets that are sent. The recipient's device plays the packets that are received, but when packets are dropped the played voice data may be very difficult to understand, and depending on how many packets are dropped, may include periods of silence when the speaker cannot be heard at all. When voice data is not understood, the recipient may have to wait to obtain the floor and then request that the sender repeat himself or herself.
Additionally, a recipient who is in a noisy environment or who is preoccupied with another activity may not hear an incoming network-based instant connect call at all and may never know that a sender attempted to reach him or her. Missing an instant connect call altogether could have negative consequences for both personal and business related matters.
The problem of packet loss during voice communication is not exclusive to half-duplex communication; indeed, the problem applies to full-duplex voice sessions in which voice data can be carried both directions simultaneously on a single channel, such as a wireless or wireline telephone call. During a full-duplex call occurring over an IP network, packet loss may occur resulting in the same poor user experience previously described. In this situation, while it is easier for a recipient to ask the speaker to repeat him or herself, there are situations where it may disrupt communication or be otherwise undesirable to do so.